“I heard an explosion. It rattled the windows. I didn’t think a lot about it,” said Debbie Knight, who works at Grace Vineyard Church about a block away from the scene. “Not even a minute or two later tons of ambulances, sirens going off everywhere.”

The burned workers were rushed to the Parkland Hospital Burn Center in Dallas. “One of them was flown by air, one of them by ground. We don’t know the extent of their injuries right now,” said Collett.

While investigators believe there was an accumulation of fumes, the Fire Marshal is still working to determine exactly what sparked the fire.